1. Field of the Invention
The present invention relates to the field of liquid crystal displaying, and in particular to a graphene transparent conductive layer and a CF (Color Filter) substrate having the conductive transparent layer and a manufacturing method thereof.
2. The Related Arts
Heretofore, a commonly used transparent conductive material is a metal oxide mixed transparent conductive material, such as indium tin oxide (ITO), indium zinc oxide (IZO), and aluminum-doped zinc oxide (AZO), among which the most commonly used one is the ITO transparent conductive material that has a light transmittance as high as 90%. However, element indium is a rare and expensive metal and the manufacture of ITO film requires high degree of vacuum and a relatively high temperature. The ITO film so obtained is brittle, making it difficult to make a flexible electrode. These limit further development of the ITO transparent conductive material.
Recently, researches revealed that graphene is novel carbon based material having a two-dimensional honeycomb structure formed by a single layer of densely packed carbon atoms. Graphene is the thinnest but hardest nanometer material that is currently known and is almost perfectly clear, absorbing 2.3% of light and having an electric resistivity of around 10−6Ω·cm, which is lower than that of copper or silver, making it a material of lowest electric resistivity that is currently known, and can be manufactured by various processes, such as chemical vapor deposition (CVD), micro-machine exfoliation, and epitaxial growth. Since graphene has an electrical conductivity that matches ITO and has a light transmittance as high as 97% and also since graphene has mechanical strength and flexibility both superior to the ITO transparent conductive material, graphene can be used completely in place of ITO in making a transparent conductive electrode or conductive layer. Further, graphene made with a CVD process is of low manufacture cost, requiring no high temperature and high pressure, and the technique for transferring graphene so manufactured to a substrate to serve as a transparent electrode or a transparent conductive layer is getting mature. Compared to the ITO transparent conductive materials, graphene has a wider and more prosperous future in flexible displaying.
It is thus desired to provide a graphene transparent conductive layer having various parameters that are all suitable to replace the ITO transparent conductive layer for use in an CF substrate of a liquid crystal display in order to acquire an electrode of a graphene transparent conductive layer having high transmittance and excellent flexibility to accordingly improve the transmittance of a CF substrate of a liquid crystal display panel that uses graphene transparent conductive material and reduce the use of backlighting.